Fluorescent light screen



19, 9 E. YELLIN FLUORESCENT LICK- 1T SCREEN Filed July 8, 1947 5 v a m ll JL J 4i f INVENTOR. Edward Yellm Patented Aug. 19, 1952 7 2, 07,455" 7 v FLUORESCENT LIGHT SCREEN Edward Yellin, Chicago, 111.," assignor, bymesne assignments, to,Leader Electric Company, Chi-1- cago, 111., a corporation of Illinois I e I Application July 8, 1947, Serial No. 759,637"

The present invention relates generally to a screen or louvre for diffusing the light emitted from one or more sources and finds particular but by no means exclusive utility as a means for diffusing the light cast by fluorescent lamps.

In the past, the conventional light diffusion louvre has been made by assembling a number of separate slats together so as to define some sort of network. The slats may be made of sheet metal, wood, or plastic material and their spacing determines the cut-01f characteristic of the louvre. By this is meant the angle between the horizontal and the region in which light begins to radiate directly through the openings in the louvre. Because of the opaqueness of the material out of which they may be constructed, or because of the separate slat mode of construction, conventional louvres have notoriously poor light transmission properties and substantially impair the lighting efiiciency of the lamp or lamps with which they may be associated. In addition, screens or louvres constructed in a conventional manner lack structural rigidity and become very unwieldy when made in large sizes.

One object of the invention is to provide a novel light diffusion screen or louvre of the general character set forth which is relatively rigid structurally yet light in weight and exceptionally high in light transmission efiiciency.

A further object is to design a screen or louvre of the above character which is made up in integral sections or grids assembled by simple means.

Another object is to provide a screen of the foregoing type which will be susceptible of mounting in a marginal supporting frame with the grids assembled in end-to-end relation there- An additional object is to enhance the light conductive efllciency of the novel screen by making the same of translucent or light conductive plastic material.

Other objects and advantages will become apparent as the following detailed description proceeds, taken in the light of the accompanying drawings, wherein:

Fig. l is a top plan view of an illustrative light difi'usion louvre embodying the present invention.

Fig. 2 is an'enlarged fragmentary view detailing theleft-hand portion of Fig. 1.

Fig. 3 is an enlarged transverse sectional view taken in the plane of the line 3-3 of Fig. 2.

Fig. 4 is a group perspective view showing sec- 7 Claims. (01. 189-182),

tions of the screen and frame in position preparatory to assembly.

Fig. 5 is an enlarged fragmentary sectional view taken in the plane of the line 5-5 of Fig; '2. I

While the invention is susceptible of various modifications and alternative constructions, a preferred embodiment has been shown in the drawings and will be described below in considerable detail. It should be understood, however. that there is no intention to limit the invention to the specific form disclosed, but on the contrary, the intention is to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more specifically to the drawing,

there is shown an illustrative light diffusionlouvre or screen 9 comprising a plurality of individual translucent grids or sections [0, I I, I2 and I3 assembled together in end-to-end relation to define a continuous network. Each individual one of the grids constitutes an integral and substantially rigid structure comprising a plurality of intersecting ribs or bars I4 all lying generally perpendicular to the plane of the grid and having substantially uniform width and thickness, their exposed edges defining opposed outer faces on the grid and which are virtually identical. This makes the grid invertible, permitting it to be installed in the screen with either face visible frombelow and no perceptible difference between the faces being apparent to an observer standing below the screen. In the instant case, the ribs [4 may be arranged in two mutually perpendicular sets defining a series of uniformly.spaced'rectangular or square interstices. Preferably, the sections or grids are made of dimensionally stable thermoplastic material, such as polystyrene which, although translucent, possesses excellent light transmitting properties. While provision is made for rigidly securing a plurality of the grids or sections together in abutting'relation to make the louvre a sound, unitary structural entity, it might on occasion be found desirable to provide the louvre with av relatively light margnial supporting frame l5 which, in the present instance, may be made of channel stock I6 having inturned flanges l1, and which frame, when the parts are assemb led,. is adapted to snugly embrace the ends of one: set of ribs of each grid to confine said grids together in a rigid self-supporting screen struc- To .providelhighdight conductive eflioiency in:

the louvre, each grid is molded as a seamless integral unit and is so constructed that it can be assembled into the louvre with a concealed joint between itself and its neighbor, such joint possessing a light transmission efficiency substantially commensurate with that of other comparable regions in the louvre. In furtherance of such objective, one. or more .of'the end ribs of each grid areof fractional width compared to the intermediate ribs of the grid, such width in the present instance being approximately half the Width of the intermediate ribs.

Thus as an incident to assembly of two or more grids in I up or subjected to vibration.

end-to-end relation, theinjadjacentfractional width ribs overlap edgewise' and complement each other so as to define a joint ribhaving substantially the same thickness; width; and length as the intermediate ribs in either of the grids. Referring more specifically to Fig. 4-, it will be perceived that the mating rib 20 of one of the grids extends from the top surface of such: grid to a point only halfwaydown; and the companion mating rib ,21 is similarly constituted from the bottom toward the top of the adjacent grid. Thus, when the grids l0, H are united, the rib 20 overlies the rib 2i, forming a lap-joint between such grids. In order to; rigidly secure adjacent grids in the foregoing assembledrelation, eachof the, fractional width end ribs'is fashioned with a plurality of thickened portions definingintegral enlargements 2'2srspaced so that when the gridsare assembled in; the manner described the enlargements will register with eachother and cooperatewith: appropriate fastening means, the enlargements 22 happen: to" be of block-like form and have central bores 23" running therethroughfor; the receipt-of a suitable fastening pin or bolt;

In instances wheretheiframeifi is provided;

common meansis alsoprovided to's'ecur'ethe grid sections to each other and to the frame. As in.

dicated earlier herein, the-frame i" is channeled on theyinnersidaas shownat, i 6.1 The height of theiramfi is the same: as, that ofthe ribs in order to render theouter faces-oftheglouvre d ip-lush with the :fram' Therefore, theendsrof'thoserib's en-: tering; therchann'el ;of; the? frame. are: cut. down :or

groovedjasiindicated at 25. f'rom. the top and bots" tom ;to, secure the necessary; fit'in'thefrazne.v ihe grooves; or. cuts, 25. alsoapply to. the lateraLJens largementsgcr blocks 22:, enabling the latterito. fit. between, the; fianges ll: of the: frame in a. the.

same mannerras-the other rib ends;

, Wihena givenipair of:the blocks=22 istlo'dg'eda; in the channelz'of the frame: I 5;.the flanges Iili of the frame are. bored as'at .21: in alinementlwith thevbo'res 23 of'the blocks-to receive fastening means suchiasabolt 29iwhose shank passes down a through. the. associated parts to. receive: a secure ing. nut sdbelow. Now. each pair of adjoining sections of the louvre isnot only'fastened: to-- gether, but also the frame [5, making itimpo's= sible for the. sections of.the louvreto-separate either from each other or from'the louvre in case the fit of the latter in;the.frarne is not-accurate;

It will: be appaIent that the.novel louvreis an appliance whichm'aybeassembled with as many sections; ,as is desired, according to the length re quiredfor a specific'installation. A'sasse'mbled,

as-lif th: I individualv grids hadibee'nf formed 'as-a In the illustrative louvre 9;

Iclaim: V

1. In a light diffusion louvre, the combination comprising a generally rectangular supporting frame of channel cross section, a plurality of grids each formed as anintegral unit of dimensionally stable translucent thermoplastic material, each of'said' grids having first and second sets-of ribs'perpendicular to each other and of substantially uniform thickness, the ends of one of said setsof ribs'being disposed inside the channel cross section of said frame, the end ribs of said first set being approximately half the width of the intermediate ribs in said first set, said grids being assembled in coplanar abutting relation in said supporting frame with saidhalf' width of adjacent. grids disposed in edge wis'e over-lapping relation with each other, integral enlargementsat. the extr'emiti'es of said' half widthefnd ribsion each of said gridsgsaid enlargements of each said grid overlappingthoseof the adjacent grid in sai'cliframe and having-aimed bores thereinsaid-frame also having a plurality of pairs ofiaiined hol'esdisposedin registry v'rith-the ali'necl bores of respective pairs of said enlargements; and a series orcommon fasteners projecting through"cor-responding pairs of saidalined bores holes-and securing said-gridsin said frame.-

2. A light diffusionlouvre comprising, in' coinbination, a wplurali'ty of grids eachmolded as an integral-unit of translucent pla-stic material, each of said gridshavin fir'st'and second sets of ribs of substantially uniformthickness, all of said ribs being perpendicular to the general plane of said louv'r-e', the e'nd ribs of said firstset being'of fracti'onaL width compared to'- the intermediate ribsin 'said-first'set, saidgrids being assembled in coplanar abutting relationwith said fral'ztional width ribs-of adjacent grids disposed in edgewise overlapping relation with each other, block like enlargements integral with said fractional width end ribs,said enlargements of each' said-grid over lapping those of 'thleadjacent-grid in said louvre,

and fastening meanscoacting with said overla'p=" ping enlargements and securing said grids' t'o'-' self-supporting louvre rstruc' gether in a rigid ture.

'3. In a'ilight diifusion louvr e of thecharacter setf forth, a translucent plastic' 'g'rid molded asan integral unit and comprising the' combination or a first set of ribs of substantially uniform thickness, 'a-second set of ribs also of substantially uniform thickness and mutually perpendicular; to

said first set, said ribs having'exposed'edgeskdefining substantially identical opposed' vouter-faces on said grid, the. end ribs of said first set being of fractional widthcom-pared tothe intermediate I with said fr'a'ction'al width and ribs' andsuscepti- ,ble of overlapping as said grid and similar grids" are assembled end -to end; said enlargements has.

ing preformed holes forrec'eiving'meansfor securing said grids" in assembled relation inthe louvre. -V w 4.. ma light dino oniouvre, agrid "molded as an integral invertible unit of dimensionally stable thermoplastic material, said grid comprising, in combination, a first set of ribs of substantially uniform thickness, 3, second set of ribs also of substantially uniform thickness, all of said ribs being substantially perpendicular to the general plane of said grid and defining substantially identical faces thereon, the end ribs of said first set being approximately half the width of the intermediate ribs in said first set for edgewise overlapping of said half width ribs upon assembly of two or more of said grids in coplanar abutting relation, each said half width rib having one edge coplanar with a face of said grid and integral enlargements on said half width end ribs, each said enlargement having a bore therethrough for receiving a fastener.

5. In a light diffusion louvre, the combination comprising a pair of invertible grids each molded as an integral unit of dimensionally stable plastic material, each said grid having two intersecting sets of ribs of substantially uniform thickness and lying perpendicular to the plane of the grid, the outer ribs of one set being of fractional width compared to the intermediate ribs of said one set but each having one edge coplanar with a face of the grid, said grids being secured in coplanar abutting relation with adjacent ones of said fractional width ribs overlapping each other, an en largement on each said overlapping fractional width rib, the enlargement of one of said overlapping fractional width ribsbeing disposed in registry with that of the other overlapping fractional width rib, and a fastener disposed transversely of said overlapping fractional width ribs and engaging the registered enlargements thereof.

6. In a light diffusion louvre, the combination comprising a pair of invertible grids each molded as an integral unit of dimensionally stable plastic material, each said grid having two intersecting sets of ribs of substantially uniform thickness and lying perpendicular to the plane of the grid,

the outer ribs of one set being of fractional width compared to the intermediate ribs of said one set but each having one edge coplanar with a face of the grid, said grids being secured in coplanar abutting relation with adjacent ones of said fractional width ribs overlapping each other, an enlargement on each said overlapping fractional width rib, the enlargement of one of said overlapping fractional width ribs being disposed in registry with that of the other overlapping fractional width rib, a frame having a portion disposed in registry with said registered enlargements, and a fastener disposed transversely of and engaging said frame portion and said registered enlargements.

7. A light diffusion screen comprising, in combination, a plurality of translucent grids each molded as an integral unit of dimensionally stable plastic material, each said grid having two sets of intersecting ribs all lying substantially perpendicular to the general plane of the screen, the side surfaces of each said rib being smooth and unbroken except for intersections with other ribs, at least one end rib of one said set being of fractional width-compared to the width of the intermediate ribs in said one set but having one edge coplanar with a face of the grid, said grids being assembled together in coplanar abutting relation with the fractional width ribs of adjacents ones of said grids overlapping each other and with concealed joints between adjacent ones of said grids, and a surrounding marginal frame extending transversely of and snugly embracing the ends of said one set of ribs of each said grid and confining said grids together in a rigid selfsupporting screen structure.

EDWARD YELLIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

